Патент USA US2120056код для вставки
June 7, 1938. I. E. MCCABE 2,120,056 COMBINED RESISTOR AND SHUNT SWITCH Original Filed July 31, 1933 IN VENTOR. jKA [7y 5 6/455 _ BY ATTORNEY. Patented June 7, 1938" r . ' UNITED STATES PATENT OFFICE 2.120.050 COMBINED RESISTOR AND SHUNT SWITCH Ira E. McCabe, Chicago, Ill. Original application July 31, 1933, Serial No. 683,037. Divided and this application Febru ary 11, 1935, Serial No. 5,931 5 Claims. (Cl. 201—48) This invention. relates to improvements in switching systems and more particularly to a combined resistor and shunt switch for use in such ‘a system. This application is a division of 5 this applicant’s prior copending application Serial No. 683,037, ?led July 31, 1933. _ It is an object of this invention to provide an electric switch so constructed that when the circult is ?rst established therethrough to include 10 an electrical resistance in said circuit and upon operation of the switch to shunt out the resistance and allow the full current to pass therethrough. It is a further object of this invention _ to include a resistor in a mercury tube switch 15 which will‘be shunted out when the switch has been tilted to cause the mercury to contact the electrodes thereof. Such combined resistor and shunt switches are of advantage when delayed action is desired in 20 controlling the operation of an electric motor and more particularly in connection with controlling reversing motors as disclosed in said parent application. thereof. 1 between the opening of the running circuit and the closing of the reversing circuit and vice versa. 5 The control of such‘ motors is usually accom plished through remote control switches which open and close the motor circuits and additional mechanism is required to provide the delay neces sary between the closing of the motor circuit and 10 the operation of the motor. The additional mechanism is interposed be- _. tween the source of the current and the motor and caused to function upon the opening and closing of the remote control switch to immedi- 15 ately open the circuit to the motor and there after allow a period for slowing up or stopping of the motor before closing the reversing circuit, to provide always a positive delay in the break ing of one motor circuit and making the reversing 20 circuit, following the operation of the remote con trol switch, regardless of how rapidly the control cation. , ' It is preferable in the delay switch operating mechanism to use the repulsion relay such as dis- 25 closed in this applicant’s co-pending application, Serial No. 508,185, ?led January 12, 1931, now Patent No. 1,973,925 of September 18, 1934, which is adaptable for use with either alternating or In the drawingFlgure 1 is a view partly in front elevation and partly in diagram, illustrating an application of this invention as‘disclosed in said parent appli35 To avoid damage, or unnecessary abuse to re versing motors, or equipment operated thereby; it is often necessary or desirable to provide a delay switch is caused to operate. With these and other objects in view, reference 25 is made to the’ accompanying sheet of drawings‘ which illustrates an embodiment of this invention with the understanding that detail changes may be made without departing‘ from the scope 30 . . - direct current or the relay disclosed in this ap- 30 plicant’s co-pending application, Serial No. 500,747, ?led December 8, 1930, which may be of the transformer type permitting the use of low voltage remote control ‘equipment, and in con Figure 2 is a view in longitudinal vertical central section of this improved switch, shown in nection with the relays to employ an electrical 35 resistor in the control circuit. The resistor con the open position with parts shown in side elevation. Figure 3 is a view similar to ‘Figure 2 showing 40 this improved switch in closed position. Figure 4 is a top plan view of Figure 1. templated may be any of the resistance elements, which offers great resistance to the passage of electric current therethrough when cold, but as its temperature increases, due to the passage of 40 current therethrough its resistance decreases For a better understanding of the advantages ‘ until a large amount of current is passable. Such and peculiar construction of this improved com- elements are known in the art and one known bined resistor and shunt switch, it is deemed ad-_ as Durhy, an electric vfurnace product having as 45 visab'le to ?rst brie?y describe a practicable com- its base silicon carbide with a very high dissocia- 46 mercial application of this novel switch before defining its peculiar construction. With this object in view,‘ reference is made to Figure 1 of the drawing which shows in diagram the application tion temperature, is manufactured by the Globar Corporation of Niagara Falls, New York. The control for a. reversing motor shown in Figure 1 includes an electric motor M and two re 50 of this switch in controlling the operation of a lays comprising a rectangular core C with a sta- 50 reversing motor, as more specifically disclosed in tionary primary coil P secured to the center of this applicant's parent application, Serial No. the upper leg thereof with movable secondary 683,037. filed July 31, 1933, with the understand- coils S mounted upon the same leg on each side ing that by so doing the use of this invention is’ ,of the stationary coil P. The switch‘ carrying 55 in no way limited to this single use. arms I are pivotally mounted at I“ to the lower ’ 2 2,120,056 leg of the core C and are each secured at their upper ends to their respective secondary coils. The arms I] are extended downward on opposite sides of the lower leg to which they are pivoted and the lower ends of each arm supports a motor switch MS and a shunt switch SS, as shown, so that the weight of said switches normally main tain the coils S in contact with the coil P. The binding post is connected to one side L of the source of commercial current and also to one winding of the primary coil the other wire of which is connected through the binding post 3 to the return line L’ commercial ‘current. The binding post 2 is connected through the motor switch operated by the left hand coil S to bind ing post ii and thence through the motor to op erate it in the forward direction to the binding post 3. The binding post 22 is also connected through the motor switch MS on the right hand 20 side to the binding post 5 and thence through the motor to operate it in reverse direction to binding post 3. in this form, one end of the windings of each of the secondary coils S are connected through their respective shunt 25 switches SS to binding post ii and from thence to the remote control switch BC. The contact ‘I adapted to be engaged by the remote control switch is connected to the other end of the wind ing of the secondary coil upon the right of the 30 primary coil and the contact t adapted to be en 'gaged by the remote control switch is connected to the other end of the secondary coil upon the left of the primary coil. In this form, the shunt switches SS are identi 35 cal and each one is a mercury tube switch espe cially constructed to act as both a resistance ele ment and as a shunt switch, as shown in Figures switch and shunt switches are closed. The clos ing action of the shunt switch causes the mer cury 02 therein to contact the terminals '9 and i I to establish the circuit through the resistor R and as the switch is tilted the mercury itself not only shunts out the resistor R but as it submerges the resistor R also has a cooling effect and accel erates the reduction in temperature‘ of the re sistor so that upon rapid switching of the remote control BC the delay, resulting from the heating 10 of the resistor, will not be shortened. What I claim is: p i. A combined resistor and shunt switch in cluding an envelope having terminals sealed in the walls thereof, an electrical resistor having a 1 negative temperature coefficient interposed be tween the terminals to be always connected in circuit therewith, and a movable body of conduct ing ?uid which, in one position of the switch, moves away from the resistor and terminals to be 20 completely out of contact therewith, and, in an other position of the switch moves to submerge the resistor and shunt it. 2. The structure of claim 1 in which the ter minals are engaged by the fluid before the re 25 sistor is submerged. 3. The structure of claim 1 wherein the ter minals are simultaneously engaged and the cir cuit closed by the conducting ?uid before the 30 fluid engages the resistor. 4. In a mercury tube switch, a sealed‘ glass en velope containing a movable body of mercury, electric terminals sealed in one end thereof one ' above the other, the upper terminal bent at an angle within the envelope to end- in the same 35 plane and in line with the end of the lower ter minal, said lower terminal offset within the en— 2, 3 and 4. As shown, the lower terminal 9 is velope adjacent the wall thereof, and an electric provided with an o?set I0 adapted to engage one 40 end of the resistor element R and the upper ter -minal H is brought down to contact the other end of the resistor R and hold the same ?rmly in resistor having a negative temperature coefficient interposed between said oifset terminal and end of the upper terminal to be always in circuit therewith, whereby when the mercury is con tained in one end of the envelope, it is out of contact with the said terminals and resistor and upon ?owing into the other end, the mercury shunts the resistor and reduces its temperature. 5. A combined resistor and shunt switch in cluding a tiltable mercury tube switch containing a body of mercury and two spaced apart ter position between the two terminals at the bottom of the mercury tube switch. The resistor is pro 45 vided with metal caps RR to which the ter minals are welded. By this construction‘ when the remote control switch opens the circuit through a secondary coil, the weight of the switches carried thereby returns it to contact 50 with the primary coil and opens both of said switches, so that when the remote control switch reestablishes the circuit through the secondary coil, the current passes through the resistor in the open shunt switch causing a delay in the 55 movement of the secondary coil until the re sistor has increased su?iciently in temperature to allow su?lcient current to pass therethrough to repel said secondary coil, whereupon the motor minals extending thereinto normally out of con- 1 tact with the mercury, in combination with an electrical resistor having a negative temperature coei?cient interposed between the terminals to be always in circuit therewith and to be free of said mercury upon tilting the switch in one direction ~ and be submerged and shunted by said mercury upon tilting the switch in the other direction. IRA E. MCCABE.